Reference may be made to the following U.S. Pat. Nos.: 3,368,830; 3,603,616; 3,603,617; 4,155,571; 4,288,105; 4,568,109; 4,655,481; 4,676,436.
Fluid pipeline systems contain components having mating flanges which must be bolted together with multiple throughbolts in order to securely lock the components in the system. The mating of such components, such as with flanges on sections of pipe, fittings, or meters is desired to be accomplished such that the centerline of the two mating components are aligned thereby preventing the fluid flow from being undesirably disturbed or disrupted at the mating junction. In the use of flow measuring instruments, for instance, it is particularly important that the flow meter centerline is aligned with the pipeline centerline to avoid creating vortices in the fluid flow which interfere with reliable flow meter readings. With the recent advent of extremely accurate flow sensing meters, the need to align and maintain proper alignment of the meter in the pipeline becomes extremely important.
Standard industry pipe flanges include a raised face providing a sealing surface matched to the raised face of an opposite flange. It is desired that the outer diameter of the respective raised faces are aligned during installation of pipeline components. The two opposing raised face flanges contain a series of holes which are aligned for placement of respective throughbolts for mounting and locking the flanges together.
However, due to industry specified tolerance in the flange bolt hole diameters, and of the diameter of the connecting throughbolts, there exists a certain amount of available movement of the mating flanges with respect to each other even with the throughbolts in position. Thus, as the mating raised face flanges are placed in position and the throughbolts are inserted, movement of one raised face flange with respect to the other while the throughbolts are being tightened makes it nearly impossible to obtain desired pipeline component alignment. In instances where pipeline alignment is necessary such as where a fluid flow measuring instrument is inserted into the pipeline system, proper alignment would at best be randomly achieved during tightening of the throughbolts.
Various alignment devices, gauges and tools have been proposed to achieve the desired alignment. One technique utilizes a pair of identical alignment gauges each having a probing finger and an engagement with the outside diameter of the raised face portion of a respective flange. As the throughbolts are tightened in position the operator must visually observe and attempt to maintain the alignment of respective edges of the gauges and thereby hopefully attain alignment of the raised face flanges.
Another technique is to utilize a pair of identical bore alignment plates in which the boltholes are smaller in diameter than the industry standard flange boltholes. Thus, the alignment plate boltholes more closely match the outer diameter of the throughbolts so as to minimize the amount of movement in the connecting flanges as the throughbolts are locked in position.
Prior attempts are time consuming and require considerable manual manipulation of the several components during mating of the opposing flanges to maintain proper alignment thereof. In addition, each is subject to human errors in attempting to maintain the proper alignment. Accordingly, such prior techniques are not reliable in instances where a very accurate flowmeter instrument is to be mounted in the system to provide accurate and reliable fluid flow measurements.
Accordingly, it is desired to provide an alignment tool having a minimum number of components and which can be reliably used without time consuming effort. In addition, it is desired to provide such an alignment tool which self centers the opposing raised face flanges and maintains the self centering alignment while the flanges are being locked into position by tightening the throughbolts.